Pump and dishwasher including the same

ABSTRACT

A pump (8) is disclosed. The pump (8) includes a partition wall (84) configured to divide the interior of a body into two spaces, a first chamber (C1) located under the partition wall (84), the first chamber (C1) having an introduction portion (841), through which water is introduced, a second chamber (C2) located above the partition wall (84), the second chamber (C2) having a discharge portion (849), through which water is discharged, a communication hole (86) formed through the partition wall (84) to allow the first chamber (C1) and the second chamber (C2) to communicate with each other therethrough, an impeller (85) provided in the second chamber (C2) to move water to the discharge portion (849), a housing configured to define the bottom surface of the first chamber (C1), the housing being made of a conductor, a heater (H) configured to heat the housing (81), and a steam discharge (843) port formed through the first chamber (C1) to allow steam to be discharged therethrough.

This application is a Continuation of application Ser. No. 16/825,558,filed on Mar. 20, 2020, which is a Divisional of application Ser. No.16/449,887, issued as U.S. Pat. No. 10,653,290, which is a Divisional ofapplication Ser. No. 16/059,582, issued as U.S. Pat. No. 10,368,715,which is a continuation of application Ser. No. 15/314,864, issued asU.S. Pat. No. 10,092,161, which is a National Stage Application ofInternational Application No. PCT/KR2015/008586, filed on Aug. 18, 2015,which claims the benefit of Korean Patent Application No.10-2014-0109476, filed on Aug. 22, 2014, Korean Patent Application No.10-2015-0102315, filed on Jul. 20, 2015 and Korean Patent ApplicationNo. 10-2015-0102316, filed on Jul. 20, 2015, all of which are herebyincorporated by reference in their entirety for all purposes as if fullyset forth herein.

TECHNICAL FIELD

The present invention relates to a pump and a dishwasher including thesame.

BACKGROUND ART

A dishwasher is an electric home appliance machine that sprays washwater onto objects to be washed in order to remove foreign matter fromthe objects.

A conventional dishwasher generally includes a tub that defines awashing space, a rack provided in the tub to receive objects to bewashed, a spray arm configured to spray wash water to the rack, a sumpconfigured to store wash water, and a pump configured to supply the washwater stored in the sump to the spray arm.

Meanwhile, some examples of the conventional dishwasher are configuredto wash objects to be washed using heated wash water (hot water) or tosupply steam to objects to be washed in order to wash or sterilize theobjects.

In general, a dishwasher using hot water is configured to heat washwater stored in a sump using a heater provided in the sump in order togenerate hot water.

In this case, the heater is exposed in the sump with the result that theheater contacts wash water. For this reason, in the conventionaldishwasher, it is necessary to control the water level in the sump suchthat the heater is not exposed in order to prevent the heater fromoverheating.

In addition, in the conventional dishwasher, heat from the heater istransferred to wash water only when the heater contacts the wash water.As a result, foreign matter is attached to the surface of the heater,whereby the efficiency of heat exchange is reduced. Furthermore, thesurface of the heater is prone to corrosion, which also reduces thedurability of the heater.

On the other hand, a dishwasher using steam is classified as adishwasher that generates steam using a heater provided in a sump or adishwasher that generates steam using an additional steam generator.

The dishwasher that generates steam using the heater provided in thesump has the same problems as the dishwasher that generates hot waterusing the heater provided in the sump.

Meanwhile, in a case in which the steam generator includes a storageunit configured to store water and a heater provided in the storage unitto heat the water stored in the storage unit, the dishwasher thatgenerates steam using the steam generator also has the same problems asthe dishwasher that generates hot water using the heater provided in thesump.

DISCLOSURE OF INVENTION Technical Problem

The present invention is directed to a pump and a dishwasher includingthe same that substantially obviate one or more problems due tolimitations and disadvantages of the related art.

An object of the present invention is to provide a pump that is capableof simultaneously performing a function of heating wash water and afunction of circulating wash water and a dishwasher including the same.

Another object of the present invention is to provide a pump configuredto have a structure in which heat exchange between a heater and washwater is easily achieved and a dishwasher including the same.

Another object of the present invention is to provide a pump that iscapable of preventing a heater from overheating even without controllingthe level of wash water and a dishwasher including the same.

Another object of the present invention is to provide a pump that iscapable of minimizing the amount of wash water that is to be supplied inorder to generate hot water or steam and a dishwasher including thesame.

Another object of the present invention is to provide a pump that iscapable of preventing the efficiency of a heater that heats wash waterfrom being reduced and preventing the durability of the heater frombeing reduced and a dishwasher including the same.

A further object of the present invention is to provide a pump includinga detachable heater and a dishwasher including the same.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

Solution to Problem

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, apump includes a body, a partition wall configured to divide the interiorof the body into two spaces, a first chamber located under the partitionwall, the first chamber having an introduction portion, through whichwater is introduced, a second chamber located above the partition wall,the second chamber having a discharge portion, through which water isdischarged, a communication hole formed through the partition wall toallow the first chamber and the second chamber to communicate with eachother therethrough, an impeller provided in the second chamber to movewater to the discharge portion, a housing configured to define thebottom surface of the first chamber, the housing being made of aconductor, a heater configured to heat the housing, and a steamdischarge port formed through the first chamber to allow steam to bedischarged therethrough.

The pump may further include a guide configured to divide the innerspace of the first chamber into a first area, in which the steamdischarge port is located, and a second area, in which the steamdischarge port is not located, based on the water level in the firstchamber.

The first area may have a larger volume than the second area.

The heater may be configured such that the amount of heat generated by apart of the heater configured to heat a liquid in the first area isgreater than the amount of heat generated by a part of the heaterconfigured to heat a liquid in the second area.

The heater may be configured such that the length of a part of theheater configured to heat a liquid in the first area is greater than thelength of a part of the heater configured to heat a liquid in the secondarea.

The guide may protrude from the partition wall toward the housing suchthat the free end of the guide does not contact the housing.

The guide may include a base located in the first area to surround apart of the outer circumferential surface of the communication hole, afirst plate connected between one end of the base and the innercircumferential surface of the first chamber to divide the first areaand the second area from each other, and a second plate connectedbetween the other end of the base and the inner circumferential surfaceof the first chamber to divide the first area and the second area fromeach other.

The introduction portion may be located in the first area.

The guide may include a first base located in the second area tosurround a part of the outer circumferential surface of thecommunication hole, a first plate connected between one end of the firstbase and the inner circumferential surface of the first chamber todivide the first area and the second area from each other, and a secondplate connected between the other end of the first base and the innercircumferential surface of the first chamber to divide the first areaand the second area from each other.

The introduction portion may be located in the second area.

The housing may be detachably mounted to the body.

The pump may further include a valve provided in the steam dischargeport to allow a fluid in the first chamber to be discharged to theoutside and to prevent a fluid from being introduced into the firstchamber.

The heater, the housing, the first chamber, and the second chamber maybe sequentially stacked in a height direction of the body such that theheater, the housing, the first chamber, and the second chamber arearranged vertically.

In another aspect of the present invention, a dishwasher includes a tubconfigured to receive objects to be washed, a spray arm configured tospray wash water onto the objects to be washed, a steam supply unitconfigured to supply steam to the tub, a sump configured to store washwater, and a pump configured to supply the wash water stored in the sumpto the spray arm, wherein the pump includes a body, a partition wallconfigured to divide the interior of the body into two spaces, a firstchamber located under the partition wall, the first chamber having anintroduction portion communicating with the sump, a second chamberlocated above the partition wall, the second chamber having a dischargeportion communicating with the spray arm, a communication hole formedthrough the partition wall to allow the first chamber and the secondchamber to communicate with each other therethrough, an impellerprovided in the second chamber to move wash water to the dischargeportion, a housing configured to define the bottom surface of the firstchamber, the housing being made of a conductor, a heater configured toheat the housing, and a steam discharge port configured to allow thefirst chamber and the steam supply unit to communicate with each othertherethrough.

The dishwasher may further include a guide configured to divide theinner space of the first chamber into a first area, in which the steamdischarge port is located, and a second area, in which the steamdischarge port is not located, based on the water level in the firstchamber.

The first area may have a larger volume than the second area.

The heater may be configured such that the amount of heat generated by apart of the heater configured to heat a liquid in the first area isgreater than the amount of heat generated by a part of the heaterconfigured to heat a liquid in the second area.

The introduction portion may be located in the first area, and the guidemay include a base located in the first area to surround a part of theouter circumferential surface of the communication hole, a first plateconnected between one end of the base and the inner circumferentialsurface of the first chamber to divide the first area and the secondarea from each other, and a second plate connected between the other endof the base and the inner circumferential surface of the first chamberto divide the first area and the second area from each other.

The introduction portion may be located in the second area, and theguide may include a first base located in the second area to surround apart of the outer circumferential surface of the communication hole, afirst plate connected between one end of the first base and the innercircumferential surface of the first chamber to divide the first areaand the second area from each other, and a second plate connectedbetween the other end of the first base and the inner circumferentialsurface of the first chamber to divide the first area and the secondarea from each other.

The dishwasher may further include a second base located in the firstarea to surround the outer circumferential surface of the communicationhole and to connect one end of the first base to the other end of thefirst base, wherein the distance from the partition wall to a free endof the second base may be less than the distance from the partition wallto a free end of the first base.

The housing may be detachably mounted to the body.

The dishwasher may further include a valve provided in at least one ofthe steam discharge port and the steam supply unit to allow a fluid inthe first chamber to be discharged to the outside and to prevent a fluidfrom being introduced into the first chamber.

The heater, the housing, the first chamber, and the second chamber maybe sequentially stacked in a height direction of the pump such that theheater, the housing, the first chamber, and the second chamber arearranged vertically.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

Advantageous Effects of Invention

The present invention has the effect of providing a pump that is capableof simultaneously performing a function of heating wash water and afunction of circulating wash water and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpconfigured to have a structure in which heat exchange between a heaterand wash water is easily achieved and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpthat is capable of preventing a heater from overheating even withoutcontrolling the level of wash water and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpthat is capable of minimizing the amount of wash water that is to besupplied to generate hot water or steam and a dishwasher including thesame.

In addition, the present invention has the effect of providing a pumpthat is capable of preventing the efficiency of a heater that heats washwater from being reduced and preventing the durability of the heaterfrom being reduced and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpincluding a detachable heater and a dishwasher including the same.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a view showing an example of a dishwasher according to thepresent invention;

FIG. 2 is a view showing an example of a pump according to the presentinvention;

FIG. 3 is a view showing an example of a structure in which a body and aheater assembly are coupled to each other;

FIGS. 4 to 6 are views showing an example of a partition wall providedat the pump;

FIGS. 7 and 8 are views showing another embodiment of the partitionwall; and

FIGS. 9 to 12 are views showing a pump and a dishwasher according toanother embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

All terms disclosed in this specification correspond to general termsunderstood by persons having ordinary skill in the art to which thepresent invention pertains unless the terms are specially defined. Ifthe terms disclosed in this specification conflict with general terms,the terms may be understood on the basis of their meanings as used inthis specification.

It should be noted herein that the construction and control method of adevice which will hereinafter be described are given only forillustrative purposes, and that the protection scope of the invention isnot limited thereto. Wherever possible, the same reference numbers willbe used throughout the drawings to refer to the same or like parts.

The present invention relates to a pump 8 that is capable ofsimultaneously performing a function of moving wash water and a functionof heating wash water and a device including the same. FIG. 1 is a viewshowing a case in which the pump 8 according to the present invention isincluded in a dishwasher by way of example.

The pump 8 according to the present invention may be included in variouskinds of devices in addition to the dishwasher. Hereinafter, however, acase in which the pump 8 is included in a dishwasher 100 will bedescribed for the convenience of description.

As shown in FIG. 1 , the dishwasher 100 may include a cabinet 1, a tub11 provided in the cabinet 1 to define a washing space, spray arms 3 and5 configured to spray wash water to objects to be washed, and a pump 8configured to supply wash water to the spray arms 3 and 5.

Racks, in which objects to be washed are received, may be provided inthe tub 11. The racks may include an upper rack 191 provided in an upperarea of the tub 11 and a lower rack 193 provided below the upper rack191.

The tub 11 is opened and closed by a door 16 provided at one surface ofthe cabinet 1 such that a user opens the door 16 and withdraws the racks191 and 193 from the tub 11.

In a case in which the racks include the upper rack 191 and the lowerrack 193, the spray arms 3 and 5 may include an upper arm 3 configuredto spray wash water to the upper rack 191 and a lower arm 5 configuredto spray wash water to the lower rack 193.

Wash water sprayed to objects to be washed by the spray arms 3 and 5(wash water left in the tub 11) may be collected in a sump 13.

The sump 13 is provided under the tub 11 to store wash water. The sump13 may be partitioned from the tub 11 by a sump cover 15. In this case,the sump cover 15 may be provided with a collection hole 151, throughwhich the interior of the tub 11 communicates with the interior of thesump 13.

Meanwhile, the sump 13 is connected to a water source (not shown)through a water supply channel 135. The water supply channel 135 may beopened and closed by a water supply valve 136, which is controlled by acontroller (not shown).

The wash water stored in the sump 13 is discharged out of the dishwasherthrough a drainage channel 137 and a drainage pump 139.

The wash water stored in the sump 13 is supplied to the spray arms 3 and5 through the pump 8 and a supply channel 7. The supply channel 7 mayinclude a connection channel 77 connected to the pump 8, a first supplychannel 71 connected between the connection channel 77 and the upper arm3, and a second supply channel 73 connected between the connectionchannel 77 and the lower arm 5.

The upper arm 3 may be rotatably coupled to the first supply channel 71,and the lower arm 5 may be rotatably coupled to the second supplychannel 73.

The first supply channel 71 and the second supply channel 73 divergefrom the connection channel 77. In this case, a change-over valve 75,configured to open and close the first supply channel 71 and the secondsupply channel 73, may be provided at the point of the connectionchannel 77 from which the first supply channel 71 and the second supplychannel 73 diverge.

The pump 8 may include a body 82 fixed in the cabinet 1, a partitionwall 84 configured to partition the inner space of the body 82 into afirst chamber C1 and a second chamber C2, a communication hole 86 formedthrough the partition wall 84 to allow the first chamber C1 and thesecond chamber C2 to communicate with each other therethrough, anintroduction portion 841 connected between the sump 13 and the firstchamber C1, a discharge portion 849 connected between the second chamberC2 and the connection channel 77, an impeller 85 provided in the secondchamber C2, and a heater assembly H provided at the bottom surface ofthe first chamber C1.

As shown in FIG. 2 , the body 82 may be formed in a cylinder shape thatis open at upper and lower surfaces thereof. A cover 823 is provided atan opening surface (the upper surface of the second chamber C2) 821provided at the upper part of the body 82, and the heater assembly H isseparately coupled to an opening surface (the bottom surface of thefirst chamber C1) 825 provided at the lower part of the body 82.

Since the heater assembly H forms the bottom surface of the firstchamber C1, the pump 8 may simultaneously perform a function of heatingwash water and a function of circulating wash water. In addition, sincethe heater assembly H is separately coupled to the body 82 from outsidethe pump 8, the heater assembly H may be easily assembled to ordisassembled from the body 82 of the pump 8.

The impeller 85 moves wash water, introduced from the first chamber C1into the second chamber C2 through the communication hole 86, to thedischarge portion 949. The impeller 85 may be rotated by a drive unit 86provided outside the body 82.

The drive unit 87 may include a motor 871 fixed to the cover 823. Arotary shaft 873 of the motor 871 may be fixed to the impeller 85through the cover 823.

As shown in FIG. 3 , the heater assembly H may include a housing 81 thatdefines the bottom surface of the first chamber C1, and a heater 83provided outside the first chamber C1 to heat the housing 81.Consequently, the heater 83, the housing 81, the first chamber C1, andthe second chamber C2 are sequentially stacked in a height direction ofthe body 82 such that the heater 83, the housing 81, the first chamberC1, and the second chamber C2 are arranged vertically.

The housing 81 may be made of a conductor, such as a metal, such thatthermal energy generated by the heater 83 can be effectively supplied towash water in the first chamber C1.

The housing 81 may include a receiving groove 811, in which the heater83 is received such that the heater 83 is located outside the firstchamber C1, and a fastening portion 812, through which the housing 81 isfixed to the body 82.

The receiving groove 811 may be formed in a shape that is capable ofmaximizing the surface area of the housing 81 that exchanges heat withwash water. FIG. 3 shows a case in which the receiving groove 811protrudes toward the interior of the first chamber C1 by way of example.

The pump 8 may further include a heater cover 815 fixed to the housing81, in order to prevent the heater 83, which is received in thereceiving groove 811, from being exposed outside the receiving groove811.

The heater cover 815 prevents wash water or foreign matter from beingsupplied to the heater 83, and also prevents components of thedishwasher disposed around the pump 8 from directly contacting theheater 83.

The fastening portion 812 may include a first extension portion 8121extending from the edge of the receiving groove 811 in a direction inwhich the first extension portion 8121 becomes more distant from thereceiving groove 811, and a second extension portion 8123 configured tocouple the first extension portion 8121 to the lower opening surface825.

The second extension portion 8123 may be formed by bending the firstextension portion 8121. In this case, the first extension portion 8121supports one end of the body 82 at which the lower opening surface 825is provided, and the second extension portion 8123 may receive thecircumferential surface of the body 82.

A support portion 827, which protrudes from the body 82, may be providedat the circumferential surface of the body 82. In this case, thefastening portion 812 may further include third extension portions 8125configured to couple the second extension portion 8123 to the supportportion 827.

The third extension portions 8125 may be provided at the free end of thesecond extension portion 8123 such that the third extension portions8125 are spaced apart from each other by a predetermined distance 8127.

Since the housing 81 defines the bottom surface of the body 82 (thebottom surface of the first chamber C1) as described above, the washwater in the first chamber C1 may leak through the fastening portion812. For this reason, it is necessary to prevent the wash water,discharged from the first chamber C1, from moving to the heater 83. Tothis end, a flange 817 may be further provided at the housing 81.

The flange 817 may be provided at any position on the housing 81 as longas the flange 817 can perform the above-mentioned function. FIG. 3 showsa case in which the flange 817 is provided at the first extensionportion 8121 by way of example.

The flange 817, which is shown in FIG. 3 , is characterized in that theflange 817 protrudes from the edge of the first extension portion 8121toward the bottom surface of the cabinet 1 to surround the circumferenceof the receiving groove 811. Consequently, wash water left on thesurface of the second extension portion 8123 moves through the flange817 in direction in which the wash water becomes more distant from theheater 83. Even when the wash water in the first chamber C1 leaksthrough the fastening portion 812, therefore, the wash water isprevented from moving to the heater 83.

The heater 83 may include a heater body 831 configured to generatethermal energy when electric current is supplied to the heater body 831,and a first terminal 833 and a second terminal 835 configured to supplyelectric current to the heater body 831. The first terminal 833 and thesecond terminal 835 may be exposed outside the receiving groove 811, andthe heater body 831 may be prevented from being exposed outside thereceiving groove 811 by the heater cover 815.

Since the heater 83 is located outside the first chamber C1, the heater83 does not contact wash water. Consequently, it is possible to preventthe efficiency of heat exchange between wash water and the heater frombeing reduced due to foreign matter attached to the surface of theheater 83 or to prevent the surface of the heater 83 from beingcorroded, thus preventing the durability of the heater 83 from beingreduced.

A positioning portion 89 may be further provided at the pump 8 in orderto easily couple the heater assembly H to the body 82. The positioningportion 89 may include a protrusion 891 provided at the support portion827 of the body 82 and a protrusion receiving recess 893 provided in thesecond extension portion 8123 to receive the protrusion 891.

The protrusion 891 may extend in a height direction of the body 82, andthe protrusion receiving recess 893 may have a width equal to thedistance 8127 between one of the third extension portions 8125 andanother of the third extension portions 8125.

However, in a case in which it is necessary to uniformly maintain adirection in which the heater assembly H is assembled (for example, in acase in which it is necessary for the two terminals 833 and 835 providedat the heater 83 not to be directed to the sump 13), the protrusionreceiving recess 893 may have a width different from the distance 8127between the third extension portions 8125. FIG. 3 is a view showing acase in which the width of the protrusion receiving recess 893 isgreater than the distance 8127 between the third extension portions 8125by way of example.

In the heater assembly H having the above-described structure, since thehousing 81 forms the bottom surface of the first chamber C1, hot water(heated wash water) may be supplied to the spray arms 3 and 5 when theimpeller 85 is rotated while the heater 83 is operated (electric currentis supplied to the heater 83).

In this case, since the heater 83 heats the housing 82, which definesthe bottom surface of the first chamber C1, it is possible to preventthe heater 83 from overheating even without controlling the water levelin the first chamber C1 and to minimize the amount of wash water that isto be supplied to generate steam or hot water.

These effects may be maximized in a case in which the housing 81 of theheater assembly H forms a plane that is parallel to the bottom surfaceof the cabinet 1. That is, the above effects may be maximized in a casein which the housing 81 is fixed to the body 82 such that the housing 81forms a horizontal plane.

Since the heater assembly H is provided at the bottom surface of thefirst chamber C1, the pump 8 may function as a steam generator in a casein which only the heater 83 is operated after a predetermined amount ofwash water has been supplied to the first chamber C1.

In order for the pump 8 to perform a function of generating steam,however, it is necessary to further provide a steam discharge port 843configured to discharge the steam generated in the first chamber C1 outof the first chamber C1.

As shown in FIG. 1 , the steam discharge port 843 may communicate withthe tub 11 through a steam supply unit 6. The steam supply unit 6 mayinclude a nozzle 61 fixed to the tub 11 and a supply pipe 63 connectedbetween the nozzle 61 and the steam discharge port 843. The steamdischarge port 843 may be located at a position lower than the partitionwall 84 and higher than the introduction portion 841.

Meanwhile, in a case in which the steam discharge port 843 is providedat the first chamber C1, a valve 844 configured to prevent external airfrom being introduced into the first chamber C1 may be further providedin at least one of the steam discharge port 843 and the supply pipe 63.

When external air is introduced into the first chamber C1 through thesteam discharge port 843, the pressure of the wash water sprayed fromthe spray arms 3 and 5 may be lowered, or wash water may not be suppliedto the spray arms 3 and 5. The reason for this is because, if the valve844 is not provided in the steam discharge port 843, air may beintroduced into the first chamber C1 when the impeller 85 is rotated.

The valve 844 may be configured to discharge a fluid in the firstchamber C1 out of the first chamber C1 and to prevent an external fluidfrom being introduced into the first chamber C1. That is, the valve 844may be a check valve that opens the steam discharge port 843 (or thesteam supply unit 6) only when the pressure in the first chamber C1 isequal to or higher than a predetermined reference pressure.

In the pump 8 having the above-described structure, although the steamin the first chamber C1 may be supplied to the tub 11 through the supplypipe 63, the steam in the first chamber C1 may also be supplied to thetub through the spray arms 3 and 5 and the collection hole 151, whichcommunicate with the first chamber C1.

The characteristic whereby the steam in the first chamber C1 is suppliedto the tub through the spray arms 3 and 5, connected to the pump 8 viathe steam supply unit 6 and the supply channel 7. and through thecollection hole 151, connected to the pump 8 via the sump 13, may beadvantageous in that steam is sprayed from a plurality of points and istherefore uniformly supplied into the tub 11. However, if a steam flowchannel is too long, the steam may be condensed while flowing along thesteam flow channel. As a result, the required amount of steam may not besupplied to the tub 11.

In order to solve the above-mentioned problem, it is necessary to designthe pump 8 such that most of the steam in the first chamber C1 can besupplied to the tub 11 through the supply pipe 63. According to thepresent invention, the pump 8 may further include a guide 88 provided atthe partition wall 84 such that most of the steam in the first chamberC1 can be supplied to the tub 11 through the supply pipe 63.

FIGS. 4 to 6 are views showing an example of the guide 88.

As shown in FIG. 4 , the guide 88 protrudes from the partition wall 84toward the housing 81 such that the free end of the guide 88 does notcontact the housing 81.

The guide 88 divides the inner space of the first chamber C1 into afirst area C11, in which the steam discharge port 843 is located, and asecond area C13, in which the steam discharge port 843 is not located,based on the water level in the first chamber C1.

That is, when the water level in the first chamber C1 is higher than thefree end of the guide 88, as shown in FIG. 5 , the inner space of thefirst chamber C1 is divided into the first area C11 and the second areaC13 by the guide 88.

The volume of the first area C11 may be greater than the volume of thesecond area C13, as shown in FIG. 6 , such that the amount of steam thatis discharged out of the first chamber C1 through the steam dischargeport 843 is greater than the amount of steam that is discharged out ofthe first chamber C1 through the channel other than the steam dischargeport 843.

In this case, the heater 83 may be fixed to the housing 81 such that thelength of a part of the heater 83 located in the first area C11 isgreater than the length of a part of the heater 83 located in the secondarea C13. That is, the heater 83 may be fixed in the receiving groove811 such that the first terminal 833 and the second terminal 835 arelocated in a part of the second area C13 that projects into the housing81.

Meanwhile, in a case in which the volume of the first area C11 and thevolume of the second area C13 are set to be equal to each other, theheater 83 may be configured such that the amount of heat generated by apart of the heater 83 that is configured to heat wash water in the firstarea C11 is greater than the amount of heat generated by a part of theheater 83 that is configured to heat wash water in the second area C13.

A heater 8, which generates different amounts of heat based on theposition thereof, may be variously configured. For example, the lengthof the heater 83 provided to heat wash water in the first area C11 maybe greater than the length of the heater 83 provided to heat wash waterin the second area C13.

In another example of the heater 83 generating different amounts of heatbased on the position thereof, the sectional area of the heater 83located under the first area C11 may be greater than the sectional areaof the heater 83 located under the second area C13.

As shown in FIG. 6 , the guide 88 may include a base 884 located in thefirst area C11 to surround a part of the outer circumferential surfaceof the communication hole 86, a first plate 881 connected between oneend of the base 884 and the inner circumferential surface of the firstchamber C1 to divide the first area C11 and the second area C13 fromeach other, and a second plate 883 connected between the other end ofthe base 884 and the inner circumferential surface of the first chamberC1 to divide the first area C11 and the second area C13 from each other.

In this case, the free end of the base 884, the free end of the firstplate 881, and the free end of the second plate 883 may protrude fromthe partition wall 84 such that the free end of the base 884, the freeend of the first plate 881, and the free end of the second plate 883 donot contact the housing 81. As a result, the guide 88 may divide theinner space of the first chamber C1 into the first area C11 and thesecond area C13 only when the water level in the first chamber C1 ishigher than the free end of the guide 88. The first plate 881 and thesecond plate 883 may divide the inner space of the first chamber suchthat the volume of the first area C11 is greater than the volume of thesecond area C13.

When wash water is supplied into the first chamber C1, the guide 88divides the inner space of the first chamber C1 into the first area C11and the second area C13. When the heater 83 is operated in this state,steam is generated in both the first area C11 and the second area C13.Since the volume of the first area C11 is greater than the volume of thesecond area C13, however, most of the steam in the first chamber C1 issupplied to the tub 11 through the steam discharge port 843.

Meanwhile, the above-mentioned effects may be obtained in a case inwhich the amount of heat that the heater generates to heat the firstarea C11 is greater than the amount of heat that the heater generates toheat the second area C13 even though the volume of the first area C11and the volume of the second area C13 are equal to each other.

The guide 88 is advantageous in that most of the steam in the firstchamber C1 is supplied to the tub 11 through the steam discharge port843. However, the channel resistance in the first area C11 may begreater than the channel resistance in the second area C13 due to thebase 884 of the guide 88.

That is, the amount of wash water that moves to the communication hole86 only through the second area C13 may be greater than the amount ofwash water that moves to the communication hole 86 through the firstarea C11 due to imbalance in the channel resistance.

In a case in which the amount of wash water that moves to thecommunication hole 86 only through the second area C13 is greater thanthe amount of wash water that moves to the communication hole 86 throughthe first area C11, the wash water may not be heated rapidly. For thisreason, the introduction portion 841 may be located in the first areaC11 rather than in the second area C13.

Meanwhile, in a case in which it is not possible to locate theintroduction portion 841 in the first area C11, the guide 88 may bedesigned as shown in FIG. 7 .

The guide 88 of FIG. 7 is characterized in that the channel resistancein the first area C11 is less than the channel resistance in the secondarea C13 such that most of the wash water introduced into the firstchamber C1 moves to the communication hole 86 through the first areaC11.

That is, the guide 88 according to this embodiment may include a firstbase 885 located in the second area C13 to surround a part of the outercircumferential surface of the communication hole 86, a first plate 881connected between one end of the first base 885 and the innercircumferential surface of the first chamber C1, and a second plate 883connected between the other end of the first base 885 and the innercircumferential surface of the first chamber C1.

Referring to FIG. 8 , the channel resistance in the second area C13 isgreater than the channel resistance in the first area C11 since theguide 88 is configured to have a structure in which the first base 885is located in the second area C13. As a result, most of the wash waterintroduced into the first chamber C1 moves to the communication hole 86through the first area C11 even though the introduction portion 841 isprovided in the second area C13. According to the present invention,therefore, it is possible to configure the pump such that heat exchangebetween the heater and wash water is easily achieved through the guide88.

In addition, the first plate 881 may be provided with a firstcommunication portion 881 a, and the second plate 883 may be providedwith a second communication portion 883 a, such that the wash waterintroduced into the second area C13 can easily move to the first areaC11.

The first communication portion 881 a may be formed by bending the freeend of the first plate 881 toward the partition wall 84 in a concavefashion, and the second communication portion 883 a may be formed bybending the free end of the second plate 883 toward the partition wall84 in a concave fashion. Consequently, the length from the partitionwall 84 to the free end of the first communication portion 881 a may beless than the length from the partition wall 84 to the free end of thefirst plate 881, and the length from the partition wall 84 to the freeend of the second communication portion 883 a may be less than thelength from the partition wall 84 to the free end of the second plate883.

Unlike what was described above, however, the first communicationportion 881 a and the second communication portion 883 a may include ahole formed through the first plate 881 and a hole formed through thesecond plate 883, respectively.

Meanwhile, the guide 88 according to this embodiment may further includea second base 887 located in the first area C11 to connect one end ofthe first base 885 to the other end of the first base 885.

In this case, the second base 887 may be provided to surround the outercircumferential surface of the communication hole 86, and the distanceL2 from the partition wall 84 to the free end of the second base 887 maybe less than the distance L1 from the partition wall 84 to the free endof the first base 885.

FIGS. 9 and 10 are views showing another embodiment of the presentinvention. A dishwasher according to this embodiment includes a cabinet1 that forms the external appearance of the dishwasher, racks 191 and193 disposed in the cabinet 1 to receive dishes, spray arms 3, 31, and 5disposed in the cabinet 1 to spray wash water to the dishes, a sump 13disposed in the cabinet 1 to supply wash water to the spray arms 3, 31,and 5, a water supply channel 135 configured to supply wash water to thesump 13 or the spray arms 3, 31, and 5, a drainage channel 137configured to discharge the wash water in the sump 13 out of thedishwasher, a filter 153 installed in the sump 13 to filter wash water,and a heater assembly H installed in the sump 13 to heat wash water.

A tub 11, which defines a washing space, is provided in the cabinet 1.The tub 11 is opened and closed by a door 16.

The racks 191 and 193 are installed in the tub 11. The racks 191 and 193may include an upper rack 191 and a lower rack 193.

The spray arms 3, 31, and 5 spray wash water to the dishes. Wash wateris supplied to the spray arms 3, 31, and 5 through supply channels.

In this embodiment, the spray arms 3, 31, and 5 include a lower arm 5configured to spray wash water to the lower rack 193, an upper arm 3located under the upper rack 191 to spray wash water to the upper rack191, and a second upper arm 31 located above the upper rack 191 to spraywash water to the upper rack 191.

The supply channels may include a first supply channel 71 configured tosupply wash water to the lower arm 5, a second supply channel 73configured to supply wash water to the upper arm 3, and a third supplychannel 78 configured to supply wash water to the second upper arm 31.The supply channels 71, 73, and 78 may be opened and closed by achange-over valve 75.

FIG. 9 shows a case in which wash water is supplied from the sump 13 tothe spray arms 3, 31, and 5. Unlike the figure, wash water may bedirectly supplied to the spray arms 3, 31, and 5 through the watersupply channel 135.

The water supply channel 135 is provided to supply wash water to thesump 13. In this embodiment, wash water is supplied to the sump 13 viathe filter 153.

The drainage channel 137 is provided to discharge the wash water storedin the sump 13 out of the dishwasher. A drainage pump 139 is provided inthe drainage channel 137.

The filter 153 filters foreign matter from the wash water. The filter153 is disposed in a wash water flow channel through which wash water isintroduced from the tub 11 to the sump 13.

To this end, a filter installation portion 131, at which the filter 153is installed, may be formed at the sump 13. In this case, the filterinstallation portion 131 may be connected to the sump 13 via a filterchannel 132.

The sump 13 includes a first chamber C1 configured to store wash waterand a pump 8 configured to move the wash water stored in the firstchamber C1 to the change-over valve 75 such that the wash water issupplied to the spray arms 3, 31, and 5.

The pump 8 includes a motor 871 and an impeller 85 configured to berotated by the motor 871. During the rotation of the impeller 86, thewash water stored in the first chamber C1 is introduced into a secondchamber C2, in which the impeller 86 is located, and is then supplied tothe spray arms 3, 31, and 5 via a connection channel 77.

Meanwhile, the first chamber C1 communicates with the tub 11 through asupply pipe 63 and a nozzle 61. Consequently, steam generated by theheater assembly H is supplied to the tub 11 through the supply pipe 63and the nozzle 61.

The steam generated in the first chamber C1 may be supplied to the tub11 through the filter channel 132 and the filter installation portion131 instead of the nozzle 61. That is, the sump 13 is connected to thetub 11 through the supply pipe 63 and the filter channel 132.

As shown in FIGS. 11 and 12 , the heater assembly H includes a housing81 installed outside the sump 13 to heat the wash water stored in thefirst chamber C1, a heater 83 located outside the sump 13 to heat thehousing 81, and a temperature control module configured to control theelectric power applied to the heater 83 based on the temperature of theheater 83.

The housing 81 is installed at the bottom surface of the sump 13 suchthat the housing 81 tightly contacts the bottom surface of the sump 13.The housing 81 transfers heat to the first chamber C1, which is disposedabove the housing 81. The housing 81 may be variously formed based onthe shape of the sump 13. For example, the housing 81 may have a largearea in order to uniformly transfer heat to the entirety of the firstchamber C1.

The housing 81 may be made of a material, such as aluminum or copper,which exhibits high thermal conductivity. The housing 81 may be providedwith a receiving groove 811, in which the heater 83 is received.

The heater 83 may be formed in a ring shape, and the receiving groove811 may be formed in a shape corresponding to the shape of the heater83.

The temperature control module includes a temperature fuse 94 configuredto regulate electric power based on the heat received from the heater 83and a wire 95 connected between the temperature fuse 94 and the heater83.

The temperature control module may further include a thermal bridge 96and a heater cover 815 in order to easily install the temperature fuse94. The thermal bridge 96 is disposed between the heater 83 and thetemperature fuse 94 to transfer heat from the heater 83 to thetemperature fuse 94.

The heater cover 815 is assembled to the housing 81 to minimize exposureof the heater 83, which is received in the receiving groove 811, to theoutside.

In this embodiment, heat is transferred to the temperature fuse 94through the thermal bridge 96. Alternatively, the temperature fuse 94may directly contact the heater 83 such that heat from the heater 83 isdirectly transferred to the temperature fuse 94. In this embodiment, itis possible to easily replace the heater assembly H when the heaterassembly H malfunctions since the heater assembly H is exposed outsidethe sump 13.

As is apparent from the above description, the present invention has theeffect of providing a pump that is capable of simultaneously performinga function of heating wash water and a function of circulating washwater and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpconfigured to have a structure in which heat exchange between a heaterand wash water is easily achieved and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpthat is capable of preventing a heater from overheating even withoutcontrolling the level of wash water and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpthat is capable of minimizing the amount of wash water that is to besupplied to generate hot water or steam and a dishwasher including thesame.

In addition, the present invention has the effect of providing a pumpthat is capable of preventing the efficiency of a heater that heats washwater from being reduced and preventing the durability of the heaterfrom being reduced and a dishwasher including the same.

In addition, the present invention has the effect of providing a pumpincluding a detachable heater and a dishwasher including the same.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

The invention claimed is:
 1. A dishwasher comprising: a tub configuredto receive objects to be washed; a spray arm configured to spray waterto the objects to be washed; a sump configured to store water; a supplyunit configured to supply steam to the tub; a pump configured to supplythe water stored in the sump to the spray arm, the pump comprising: abody; a partition wall configured to divide an interior of the body intoa first chamber and a second chamber, the first chamber having anintroduction portion communicating with the sump, and the second chamberhaving a discharge portion communicating with the spray arm; acommunication hole formed through the partition wall to allow the firstchamber and the second chamber to communicate with each other; animpeller provided in the second chamber to make water move to thedischarge portion; a heater configured to heat the water inside thefirst chamber; and a steam discharge port configured to discharge steamgenerated in the first chamber to the supply unit, wherein the steamdischarge port is located in the first chamber at a position higher thanthe introduction portion.
 2. The dishwasher according to claim 1,wherein the supply unit comprises a nozzle fixed to the tub; and asupply pipe connecting the nozzle with the steam discharge port.
 3. Thedishwasher according to claim 2, further comprising a valve provided inthe steam discharge port to allow the steam in the first chamber to bedischarged to the supply pipe.
 4. The dishwasher according to claim 2,further comprising a valve provided in the supply unit to allow thesteam in the supply pipe to be discharged to the tub.
 5. The dishwasheraccording to claim 3, wherein the valve is a check valve that opens thesteam discharge port 843 only when the pressure in the first chamber isequal to or higher than a predetermined reference pressure.
 6. Thedishwasher according to claim 1, further comprising a guide thatprotrudes from the partition wall toward a bottom surface the firstchamber such that a free end of the guide does not contact the housing,wherein the guide is configured to divide an inner space of the firstchamber into a first area, in which the steam discharge port is located,and a second area, in which the steam discharge port is not located,based on a water level in the first chamber.
 7. The dishwasher accordingto claim 6, wherein the first area has a larger volume than the secondarea.
 8. The dishwasher according to claim 7, wherein a length of a partof the heater configured to heat water in the first area is longer thana length of a part of the heater configured to heat water in the secondarea.
 9. The dishwasher according to claim 8, wherein the guidecomprises: a base located in the first area to surround a part of anouter circumferential surface of the communication hole; a first plateconnected between one end of the base and an inner circumferentialsurface of the first chamber to divide the first area and the secondarea from each other; and a second plate connected between the other endof the base and the inner circumferential surface of the first chamberto divide the first area and the second area from each other.
 10. A pumpcomprising: a body; a partition wall configured to divide an interior ofthe body into two spaces; a first chamber located under the partitionwall, the first chamber having an introduction portion, through whichwater is introduced; a second chamber located above the partition wall,the second chamber having a discharge portion, through which water isdischarged; a communication hole formed through the partition wall toallow the first chamber and the second chamber to communicate with eachother; an impeller provided in the second chamber to make water move tothe discharge portion; a heater configured to heat the water inside thefirst chamber; and a steam discharge port configured to discharge steamgenerated in the first chamber by the heater to the outside of the body,wherein the steam discharge port is located in the first chamber at aposition higher than the introduction portion.